Sorry @dejwi, I just saw your comments! A Frameworks Engineer has acknowledged the issue. Hopefully, it'll be fixed in an upcoming update.

Sorry, the comments were posted twice after I got a post message error. Please delete my 3 comments including this one.

Done, I have filed report FB20287404 as "SpriteKit performance regression on iOS 26". Long live SpriteKit.

Done, I have filed report FB20287404 as "SpriteKit performance regression on iOS 26". Long live SpriteKit.